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Integrating wide swath sonar with the portable AUV
GeoAcoustics Ltd and Hydroid Inc have been integrating the GeoSwath Plus wide swath sonar with the Remus 100 man-portable AUV.In late 2009 a 500kHz GeoSwath Plus (GS+) was deployed on a Remus 100 for a survey of Buzzards Bay, Massachusetts, USA.
The AUV was also equipped with a full navigation package including a Kearfott T16 Inertial navigation System aided by an RDL Doppler Velocity Log. This configuration allows the man-portable Remus 100 to collect high resolution, high accuracy co-registered bathymetry and side scan survey data.
Two surveys were carried out, four lines 500m long for system calibration in Megansett Harbour and eight lines 700m long for a survey trial in the bay, with the lines running across the shipping channel leading to Cape Cod Canal. Lines were run at 3m constant depth and the bathymetry data was processed in the GS+ software using an 80m swath width. The excellent quality of the navigation and depth mapping was demonstrated in the survey results, with clear definition of a 40cm high 10m period sand wave field in the shipping channel.
This survey trial was the end result of a successful integration project to combine the most widely used interferometric mapping sonar with the most successful small AUV, both systems manufactured by Kongsberg Maritime companies.
The GeoSwath Plus sonar allows wide swath bathymetry and side scan data to be collected from small vessels of opportunity in water depths up to 200m beneath the transducers. The system was designed to meet the need for a wide swath system capable of high productivity surveys in very shallow waters, and can achieve swath widths over 12 times water depth. The GeoSwath provides high accuracy, high resolution bathymetry (depth measurement accuracy exceeding the latest IHO specifications), and co-registered side-scan data. GeoSwath versions are now also available for mounting on small ROVs and AUVs.
For more information, visit www.km.kongsberg.com/geoacoustics